More bang for bugs

December 17, 2012

For every species of bird, there are 83 species of insect. And for every species of mammal there are 312 species of arthropods,” said Basset

“While we assign immense resources to map our genes, resolve sub-atomic structures and search for extra-terrestrial life, we invest so much less to discover who else accompanies us on the Earth,” said Smithsonian research scientist Yves Basset who organized the most extensive count of insects to date in Panama's San Lorenzo Protected Area. During 2003-2004 scientists sampled the rainforest from canopy cranes, inflatable platforms, balloons, climbing ropes and along the forest floor to collect a total of 130,000 insects.

There are more insects than any other kind of multicellular terrestrial life, but insects are extremely difficult to find, identify and count, so the total number of insect species on the planet remains a mystery. “Our study concludes that for every species of vascular plant in this rainforest in Panama there are 20 species of insects. For every species of bird, there are 83 species of insect. And for every species of mammal there are 312 species of arthropods,” said Basset.

It took a collaboration of 102 researchers from 21 countries to sort and identify this massive collection, which ended up totaling 6,000 species of insects. From the area sampled, scientists scaled up the number to arrive at an estimate of 25,000 insect species for the entire forest.

Insects were well represented in the smaller samples. “This is good news,” said Basset. “A one hectare sample may be enough to get an idea of the arthropod richness of a region. Our results also confirmed the close correspondence between the number of plant species and the number of insect species which confirmed past ideas that we can base global estimates of species numbers on the number of plant species.”

This study by Basset and 37 co-authors, was published in Thursday's edition of Science magazine.